Energy storage battery bracket plate and manufacturing method thereof

Abstract

The invention discloses an energy storage battery bracket plate, which is integrally formed by using a glass fiber composite material, and is characterized in that the energy storage battery bracket plate comprises a first flange and a second flange which are the same, and the first flange and the second flange are connected through a web plate; cavities are formed in the web plate and the first flange, a plurality of rib plate supports are arranged in the web plate, and the glass fiber volume content of the energy storage battery bracket plate is 55%-60%. The invention further discloses a manufacturing method of the energy storage battery bracket plate. The bracket plate is made of glass fibers with the fiber volume content of 55%-60%, the composite bearing structure, the flanges, the web and the cavity structure are integrally formed, the battery load in the vertical direction is borne, the weight of the bracket plate is reduced, the energy density of an energy storage system is improved, corrosion resistance is improved, the bracket plate adapts to severe environments such as salt mist and damp and hot environments, and the heat conduction coefficient is reduced; thermal runaway spreading speed is slowed down, high mechanical property is guaranteed, and the structural bearing requirement of the battery pack is met.

Description

Technical Field

[0001] This invention relates to the field of new energy storage equipment structure technology, and in particular to an energy storage battery bracket plate and its manufacturing method. Background Technology

[0002] Existing energy storage battery brackets mainly use metal materials (such as steel and aluminum), engineering plastics, or traditional fiber-reinforced composite materials (FRP). Among them, metal brackets are heavy (accounting for 15%-30% of the total system weight), resulting in low system energy density. They are also prone to corrosion in harsh environments such as salt spray (corrosion rate > 0.1 mm / year). Their high thermal conductivity (thermal conductivity coefficient ≥ 160 W / (m·K)) will accelerate the spread of thermal runaway, which contradicts the requirements of energy storage systems for lightweighting and safety. Engineering plastic brackets have insufficient mechanical properties with a bending strength < 200 MPa, which cannot meet the requirements of heavy load bearing. Traditional FRP brackets have a bending strength < 250 MPa and dimensional tolerance > ± 2 mm. Their mechanical properties are limited, and the molding process (such as hand lay-up and compression molding) has low production efficiency and poor dimensional accuracy, which cannot meet the needs of large-scale production. Summary of the Invention

[0003] The main objective of this invention is to solve the technical problems described in the background section.

[0004] In a first aspect, the present invention provides an energy storage battery bracket plate, wherein the energy storage battery bracket plate is integrally formed using glass fiber composite material, characterized in that the energy storage battery bracket plate includes identical first flange and second flange, the first flange and the second flange are connected by a web, a cavity is provided in the web and the first flange, a plurality of ribs are provided inside the web for support, and the glass fiber volume content of the energy storage battery bracket plate is 55%-60%.

[0005] Preferably, the thickness of the first flange is 8-12 mm and the width is 50-80 mm.

[0006] Preferably, the web has a thickness of 5-8 mm and a height of 100-150 mm.

[0007] Preferably, the distances between the ribs in the web are equal.

[0008] Preferably, the surface of the energy storage battery bracket plate is coated with an insulating coating, and the volume resistivity of the insulating coating is >10. 14 Ω·cm.

[0009] Preferably, the thickness of the insulating coating is 50±5μm.

[0010] Secondly, the present invention discloses a method for manufacturing an energy storage battery bracket plate as described in any one of the first aspects, the method comprising: A fiber bundle is obtained by mixing a first glass fiber and a second glass fiber, wherein the diameter of the first glass fiber is 10-12 μm and the length of the second glass fiber is 12-25 mm. The fiber bundle is immersed in a resin impregnation tank for impregnation to obtain a fiber composite material, wherein the fiber volume ratio of the fiber composite material is 55%-60%. The fiber composite material is initially shaped using a preforming mold, and then the initially shaped fiber composite material is pulled into a molding mold for curing to obtain a continuous profile. The continuous profile is sequentially cut, coated with an insulating coating, and dried to obtain the energy storage battery bracket plate.

[0011] Preferably, the step of mixing the first glass fiber and the second glass fiber to obtain a fiber bundle can be replaced by: The first glass fiber is unwound using a yarn rack, and the second glass fiber is continuously fed to the unwound first glass fiber through an unwinding device to obtain a third glass fiber. The third glass fiber is then combed through a guiding device to obtain a fiber bundle.

[0012] Preferably, the molding die is divided into a preheating zone, a curing zone, and a shaping zone along its length.

[0013] Preferably, the temperature of the preheating zone is 80-100℃, the temperature of the curing zone is 120-140℃, and the temperature of the setting zone is 100-110℃.

[0014] The energy storage battery bracket plate in this application adopts a composite load-bearing structure: the first and second flanges adopt a rectangular flat plate structure and are connected by a web plate. It is made of glass fiber with a fiber volume content of 55%-60%, which bears the vertical battery load, reduces the weight of the bracket plate, increases the energy density of the energy storage system, improves corrosion resistance, adapts to harsh environments such as salt spray and humid heat, reduces the thermal conductivity coefficient, slows down the thermal runaway propagation rate, ensures high mechanical performance, meets the structural load-bearing requirements of the battery pack, and the cavity structure is integrally molded to improve torsional and buckling resistance. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the energy storage battery bracket plate in one embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of an energy storage battery bracket plate according to an embodiment of the present invention; Figure 3 for Figure 2 Enlarged view of section A in the middle; Figure 4 This is a three-dimensional structural diagram of an energy storage battery bracket plate according to an embodiment of the present invention; Figure 5 This is a schematic flowchart of a method for manufacturing an energy storage battery bracket plate according to an embodiment of the present invention; Figure 6 This is a schematic flowchart of a method for manufacturing an energy storage battery bracket plate according to an embodiment of the present invention; Component symbols in the diagram: 1-First wing edge; 2-Second wing edge; 3-Web plate; 31-rib plate. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0017] Firstly, referring to Figure 1-4 The present invention provides an energy storage battery bracket plate, wherein the energy storage battery bracket plate is integrally molded using glass fiber composite material. The energy storage battery bracket plate includes an identical first flange 1 and second flange 2, the first flange 1 and the second flange 2 are connected by a web plate 3, a cavity is provided in the web plate 3 and the first flange 1, and a plurality of ribs 31 are provided inside the web plate 3 for support. The glass fiber volume content of the energy storage battery bracket plate is 55%-60%.

[0018] The first flange 1 has a thickness h2 of 8-12mm and a width h1 of 50-80mm. The second flange 2 has the same thickness h2 as the first flange 1, with a width h of 50-80mm and an internal cavity. The web plate 3 has a thickness h4 of 5-8mm and a height h3 of 100-150mm. The rib plate 31 has a thickness of 3-5mm. The edge of the energy storage battery bracket plate has multiple mounting holes evenly distributed for mounting the energy storage battery bracket plate on the external structure. One side of the first flange 1, the second flange 2, and the web plate 3 are on the same horizontal line to facilitate the installation of the energy storage battery bracket plate.

[0019] The mechanical properties of this energy storage battery bracket plate include a bending strength of 320 MPa, a compressive strength of 280 MPa, and an elastic modulus of 25 GPa (at 23℃). Thermal properties include a mechanical property temperature index of 129.5℃ and a heat distortion temperature (1.82 MPa) of 135℃. The flame retardant rating is UL94 V-1 (for a 2.0 mm uncoated sample). Environmental performance includes no rust after 1000 hours of salt spray testing and a bending strength decrease of <5% after 500 hours of xenon lamp aging. Dimensional accuracy includes a cross-sectional dimension tolerance of ±0.5 mm and a straightness deviation of <1 mm / m.

[0020] In this embodiment, a composite load-bearing structure (I-shaped reinforced structure, with the thickness h2 of the first flange 1 and the second flange 2 being 8-12mm, greater than the thickness h4 (5-8mm) of the web 3) is adopted. Through pre-separation (multiple ribs 31 are set in the web 3), efficient material utilization is achieved, reducing the weight by 50%-60% compared to the metal bracket plate. The first flange 1 and the second flange 2 adopt a rectangular flat plate structure, and both the first flange 1 and the second flange 2 are made of glass fiber composite material with a fiber volume content of 55%-60%. This structure bears the vertical battery load, reduces the weight of the bracket plate, increases the energy density of the energy storage system, improves corrosion resistance, adapts to harsh environments such as salt spray and humid heat, reduces the thermal conductivity coefficient, slows down the thermal runaway propagation rate, ensures high mechanical performance, and meets the structural load-bearing requirements of the battery pack. The one-piece molding of the cavity structure improves the torsional and buckling resistance performance, which is superior to traditional FRP, and meets the heavy load requirements of the energy storage system.

[0021] Preferably, the distances between the ribs 31 in the web 3 are equal.

[0022] Multiple ribs 31 with equal spacing are provided in the web 3, for example, such as Figure 1-3 As shown, there are 16 ribs 31, and the distance between each rib 31 is equal.

[0023] In this embodiment, the evenly spaced ribs 31 form a uniform support structure within the cavity of the web 3 of the bracket plate. This allows the weight of the energy storage battery and external loads to be evenly transferred to the two flanges along the plane of the web 3, avoiding local stress concentration caused by uneven spacing of the ribs 31. This effectively reduces the risk of deformation and cracking of the web 3, meeting the load-bearing requirements of the energy storage battery during long-term static storage and transportation. The design of the evenly spaced ribs 31 allows the resin to penetrate more evenly into the fiber bundle gaps during the molding process. The fiber arrangement at the connection points between the ribs 31 and the web 3 and flanges is more regular, avoiding resin impregnation blind spots caused by local structural abrupt changes. This ensures the consistency of the composite material interface bonding and further improves the overall performance of the bracket plate. In terms of mechanical properties, the structural design of the equidistant ribs 31 has a high degree of symmetry and repeatability. In the mold design and integral molding process, it can simplify the mold processing flow and reduce molding deviations caused by structural complexity. At the same time, the uniform structure ensures that the shrinkage rate of the composite material is consistent during the curing process, reducing the occurrence of defects such as warping and deformation, improving the product qualification rate, and adapting to the needs of large-scale production. While ensuring the support strength of the web 3, the equidistant ribs 31 can precisely control the amount of material used and avoid the weight increase caused by local redundant structures. Compared with non-equidistant designs, it can achieve the optimal load-bearing efficiency under the goal of lightweighting, providing support for the overall layout, space utilization, and weight reduction and energy saving of the energy storage battery pack.

[0024] Preferably, the surface of the energy storage battery bracket plate is coated with an insulating coating, and the volume resistivity of the insulating coating is >10. 14 Ω·cm.

[0025] The insulating coating has a thickness of 50±5μm, uses Nippon Paint M7000W black coating, and has a salt spray resistance of ≥1000h.

[0026] In this embodiment, the volume resistivity is >10. 14 The Ω·cm insulating coating can effectively block the current path between the energy storage battery bracket plate and the battery module and circuit, avoiding the risk of leakage and short circuit caused by conductive impurities on the bracket plate surface and exposed composite fiber. At the same time, with a precise thickness of 50±5μm, it can form a continuous and non-porous insulating barrier on the bracket plate surface, which is suitable for the long-term high-voltage and high-humidity working environment of the energy storage battery pack, and improves the overall safety and reliability of the battery pack.

[0027] Secondly, referring to Figure 5 The present invention discloses a method for manufacturing an energy storage battery bracket as described in any one of the first aspects, the method comprising: S110, the first glass fiber and the second glass fiber are mixed to obtain a fiber bundle, wherein the diameter of the first glass fiber is 10-12 μm and the length of the second glass fiber is 12-25 mm; The first glass fiber is a continuous glass fiber yarn with a diameter of 10-12μm. For example, Chongqing International Composite Materials T700 grade continuous glass fiber yarn with a diameter of 10-12μm is used. The second glass fiber is a chopped glass fiber mat with a length of 12-25mm. For example, Nanjing Jinjiu chopped glass fiber mat with a length of 12-25mm is used. This step can be replaced by: unfolding the first glass fiber using a yarn frame, continuously feeding the unfolded first glass fiber with the second glass fiber using an unwinding device to obtain a third glass fiber, and combing the third glass fiber using a guiding device to obtain a fiber bundle.

[0028] In this step, the first glass fiber (continuous fiber) ensures axial strength, while the second glass fiber (chopped strand mat) enhances transverse properties and resin impregnation. The continuous first glass fiber, unwound by the yarn frame, forms a stable load-bearing skeleton along the fiber bundle axis, ensuring excellent axial tensile and bending strength. The chopped strand mat type second glass fiber, continuously supplied by the unwinding device, evenly fills the transverse direction and gaps of the fiber bundle, compensating for the transverse performance shortcomings caused by the axial arrangement of the continuous fiber. This achieves a balanced improvement in the axial and transverse mechanical properties of the fiber bundle, avoiding the "strong axial, weak transverse" defect inherent in single-fiber structures. The chopped strand mat form of the second glass fiber has a larger specific surface area and is more loosely packed. The fiber arrangement structure increases the contact area with the resin and forms more resin penetration channels inside the fiber bundle, effectively improving the resin impregnation rate and uniformity, reducing defects such as dry spots and bubbles, and thus improving the structural density and overall mechanical stability of the subsequently molded products. Through the integrated process of unwinding the yarn frame, continuous supply from the unwinding device, and combing by the guiding device, continuous composite and regularized processing of two different forms of glass fibers is achieved. The combing function of the guiding device can avoid problems such as fiber entanglement, wrinkling, and uneven distribution during the composite process, ensuring the consistency of fiber bundle product specifications, reducing the scrap rate in the production process, and improving the efficiency of large-scale production.

[0029] S120, the fiber bundle is immersed in a resin impregnation tank for impregnation to obtain a fiber composite material, wherein the fiber volume ratio of the fiber composite material is 55%-60%; For example, in this step, the resin used is Covestro Polymers Desmodur® 44V20L polyurethane resin (viscosity 500-800 mPa·s at 25°C). This material is suitable for pultrusion processes and has high strength and aging resistance. Specifically, the fiber bundle (a mixture of fiber yarn and chopped strand mat) is fully impregnated with polyurethane resin in an impregnation tank. The resin content is controlled to achieve a fiber volume ratio of 55%-60%, allowing the fibers to form a uniform and dense load-bearing network in the resin matrix. This fully utilizes the axial strength advantage of the first glass fiber and the transverse reinforcement effect of the second glass fiber, while ensuring that the resin completely covers the fibers and fills the fiber gaps. This results in a composite material with high tensile strength, flexural strength, and excellent impact resistance. The composite material at this volume ratio has good flowability during molding, is easy to fill the mold, and can be adapted to various molding processes such as compression molding and pultrusion, reducing molding defects. If the fiber volume ratio is less than 55%, it will be difficult for the fibers to form a continuous load-bearing skeleton in the matrix, significantly reducing core mechanical properties such as axial strength and transverse stiffness. Excessive resin content can lead to unsatisfactory results in unsuitable structural components. Too much resin increases shrinkage during molding, causing warping, deformation, and internal bubbles. Increased density negates the lightweight advantage of composite materials, increases curing time and energy consumption, and excess resin overflows during molding, wasting raw materials and increasing production costs. Furthermore, if the fiber volume ratio exceeds 60%, the excessive fiber density hinders resin penetration, leading to dry spots and porosity. This significantly reduces the interfacial bonding between fibers and resin, making them prone to debonding under external forces. Consequently, the composite material exhibits decreased toughness, increased brittleness, and deteriorated impact resistance. A high fiber volume ratio also reduces molding fluidity, making mold filling difficult, especially in complex components, resulting in incomplete filling and a significantly higher scrap rate. Excessive fiber density also causes stress concentration, leading to material cracking and shortened lifespan.

[0030] S130, the fiber composite material is initially shaped using a preforming mold, and then the initially shaped fiber composite material is pulled into a molding mold for curing to obtain a continuous profile; The use of preforming molds and forming molds refers to existing pultrusion molding technology. The shape of the preforming mold is similar to the shape of the cross-section of the energy storage battery bracket plate, and the shape of the forming mold matches the shape of the cross-section of the energy storage battery bracket plate, including the forming areas of the first flange, the second flange, the web, and the ribs. Specifically, the fiber composite material is initially shaped in the preforming mold and then cured through the forming mold. The forming mold is divided into a preheating zone, a curing zone, and a shaping zone along its length. The preheating zone is 80-100℃, the curing zone is 120-140℃, and the shaping zone is 100-110℃.

[0031] S140, the continuous profile is sequentially cut, sprayed with an insulating coating and dried to obtain the energy storage battery bracket plate.

[0032] Reference Figure 6 As shown, this step includes: S141, according to the preset length, the continuous profile is cut using a cutting device to obtain the first semi-finished product; The preset length is the length required for the energy storage battery bracket plate.

[0033] S142, an insulating coating is electrostatically sprayed onto the surface of the first semi-finished product, and then the first semi-finished product is dried at a preset temperature for a preset time to obtain the energy storage battery bracket plate. The thickness of the insulating coating after drying is 50±5μm. The preset temperature is 60℃ and the preset time is 30 minutes. Specifically, an insulating coating is electrostatically sprayed onto the surface of the first semi-finished product, and then the first semi-finished product is dried at a temperature controlled at 60℃ for 30 minutes to obtain the energy storage battery bracket plate.

[0034] It should be noted that the energy storage battery bracket plate needs to be pulled by a traction device during the manufacturing process. The speed of the traction device is related to the curing speed of the fiber. For example, the speed of the traction device is set to 0.5-1m / min, and the cutting device is set behind the traction device.

[0035] In this embodiment, the main body is a glass fiber / polyurethane composite I-beam load-bearing structure, which is manufactured by pultrusion molding. The pultrusion process enables continuous production, which greatly improves the speed compared to the traditional lamination process. It also produces products with high dimensional accuracy (±0.5mm), reduces assembly errors in the later stages, and solves the problem of low production efficiency of traditional FRP brackets. It is suitable for containers and industrial and commercial energy storage systems, and can be formed in one step by pultrusion mold without additional processing.

[0036] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0037] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0038] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0039] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. An energy storage battery rack plate integrally formed using a glass fiber composite material, characterized by, The energy storage battery bracket plate comprises the same first flange and second flange connected by a web, the web and the first flange are provided with cavities, the web is internally provided with a plurality of rib plate supports, and the glass fiber volume content of the energy storage battery bracket plate is 55%-60%.

2. The energy storage battery rack plate of claim 1, wherein, The thickness of the first flange is 8-12 mm, and the width is 50-80 mm.

3. The energy storage battery rack plate of claim 1, wherein, The thickness of the web is 5-8 mm, and the height is 100-150 mm.

4. The energy storage battery rack plate of claim 1, wherein, The distance between the rib plates in the web is equal.

5. The energy storage battery rack plate of claim 1, wherein, The energy storage battery carrier plate surface is coated with an insulating coating with a volume resistivity > 10 14 Ω-cm.

6. The energy storage battery rack plate of claim 5, wherein, The thickness of the insulating coating is 50±5 μm.

7. The method of claim 1-6, wherein, The manufacturing method of the energy storage battery bracket plate comprises: Mixing first glass fibers and second glass fibers to obtain a fiber bundle, the diameter of the first glass fibers is 10-12 μm, and the length of the second glass fibers is 12-25 mm; Impregnating the fiber bundle in a resin impregnation tank to obtain a fiber composite material, the fiber volume ratio of the fiber composite material is 55%-60%; Preliminarily shaping the fiber composite material through a preforming mold, then pulling the preliminarily shaped fiber composite material into a forming mold for curing to obtain a continuous profile; Cutting, spraying an insulating coating and drying the continuous profile in sequence to obtain the energy storage battery bracket plate.

8. The method of claim 7, wherein the step of forming the energy storage battery carrier plate further comprises the step of: The step of mixing first glass fibers and second glass fibers to obtain a fiber bundle can be replaced by: ​ Unwinding the first glass fibers through a creel, continuously supplying the unwound first glass fibers with the second glass fibers through a unwinding device to obtain third glass fibers, and combing the third glass fibers through a guiding device to obtain a fiber bundle.

9. The method for manufacturing the energy storage battery bracket plate as described in claim 7, characterized in that, The forming mold is divided into a preheating zone, a curing zone and a shaping zone along the length direction.

10. The method of claim 9, wherein the step of forming the energy storage battery carrier plate further comprises the step of: The temperature of the preheating zone is 80-100℃, the temperature of the curing zone is 120-140℃, and the temperature of the shaping zone is 100-110℃. ​

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